Air-feeding apparatus for furnaces.



No. 737,(344. PATENTED SEPT. 1, 1903. c. c. MAGMILLAN a: c. A. WHYTE. AIR FEEDING APPARATUS FOR FURNAGES.

APPLIOATION I'ILED SEPT. 4, 19 02.

INVENTORS ///%7%//////////////////%//////A///// /AV//////////////%/////j ATTORNEYS E a M 47 WITNESSES: wg/W J No. *737,644. PATBNTED SEPT. 1, 1903. o. o. MACMILLAN & c. A. WHYTE.

AIR FEEDING APPARATUS FOR FURNACES.

APPLIOATION nLED SEPT. 4, 1902.

NO MODEL. 4 SHEETS-SHEET 2.

- WITNESSES: Z c WHIENTORSZZa Co In am I acmz' rz Charles .Yda'r'J/ye ATTORNEYS ma NORRIS PEYERS co wmuurno.. WASHINGTDN. o c.

No. '737,644. PATENTED SEPT. 1, 1903;

C. C. MAGMILLAN GJ. A. WHYTE.

AIR FBEDING APPARATUS POR FURNACES.

APPLIOATION PILED SEPT. 4., 1902.

NO MODEL. 4 SHEETS-SHEET 3. i

WITNESSES: INVENTORS 0%/ (bim Campellxlcmz'llan v W charlesfa'ari ytc UNiTED STATES atented September 1, 1903.

PATENT OFFICE.

COLIN CAMPBELL MACMILLAN AND CHARLES ADAIR VVIIYTE, OF PARTICK, GLASGOW, SCOTLAND.

AlR-FEEDING PPARATUS FOR FURNACES.

SPECIFICATION forming part of Letters Patent N 0. 7373644, dated September 1, 1903.

Application filed September 4:, 1902. Serial No; 122.024. (No model.)

To all whom it may conocrn:

Be it known that we,CoLIN CAMPBELL MAC- MILLAN and CHARLES ADAIR WHYTE, sub-' jects of the King of Great Britain, residing at Partick, Glasgow, Scotland, have in ven ted certain new and useful Improvements in Air- Feeding Apparatus for Furnaces, of which the following is a full and complete specification, such as will enable those skilled in the art to which it appertains to make and use the same.

The object of our invention is to provide an improved apparatus for use in connection with all kinds of furnaces, but more especially with Steaua-boiler furnaces, for preventing formation of smoke andalso to save coal or reduce the amount of coal necessarily einployed, a further object being to provide an apparatus of this class which may be used in connection with any kind or class of fuel employed.

The invention is fully disclosed in the following specification, of which the accompanying drawings form a part, in which the separate parts of our improvement aredesignated by the same reference characters in each of the views, and in which- Figure 1 is a side View, partially in section, showing the application of our improved apparatus to a Oornish boiler; Fig. 2, an end view thereof; Fig. 3, a sectional side elevation of an air-distributing box which we employ, taken on the line 3 3 of Fig. 2; Fig. 4:, a side View thereof; Fig. 5, a top plan View of an air-distributing box shown in Figs. 3 and 4, and Fig. 6 a bottom plan view thereof.

In the drawings forming part of this specification we have shown at X an ordinary steamboiler of the Cornish type, which is mounted in the usual manner and in the front end of which is a furnace-chamber X in which in the form of Construction shown are grated members X beneath which is an ash-pit X at the rear end of which is the usual transverse bridge:wall X which extends upwardly into the furnace-chamber and over which the products of combustion from the furnacechamber pass.

In the front wall of the furnace-chamber and level with the top of the grate-bars we place an air-distributing box A, which extends entirely across the f urnace-chamber and which for this and similar classes oi' boilerfurnaces is partially inside of and partially outside of the front frnace-wall X Beneath said boiler X and passing partially around the same is an escape-fine Y for the products of combustion, and passing through said escape-fine Y and longitudinally of the boiler X are the hot-air pipes K and K and these hot-air pipes are secured at their front ends to the under side of that part of the airdistributing box A which is outside of the boiler X, as clearly shown in Fig. l, and these pipes K and K are curved upwardly at the 'ear of the boiler X and pass out of the escape-fine Y into the open air and are provided at their ends with tapering ends L and L which are protected by covers or guards M and M and these hot-air pipes are also provided with sliding eXpansion-joints N and N, placed outside of the escape-fine Y and adapted to take up the expansion due to heat, and for marine and internal-combustion-chamber boilers the heating-pi pes are carried through the uptake.

At Z we have shown an ordinary steamdrum having a supply-pipe Z and connected with this supply-pipe is a small pipe P,wlich is provided with a valve R, and at the outer end of the pipe P are two nozzles O and 0 adjusted centrally with the orifices of the tapering ends L and L of the hot-air pipes K and K, and pivotally secured to the valve R is a rod S, which passes to the front of the boiler X and is adapted to be operated as shown at S or in any other desired nanner.

At the front of the air-distributing box A we provide a number of small conical holes for the admission of air, and in the top wall of the box A are a plurality of openings B, which are provided with an inwardly-swinging door 13 and this door is secured to a transverse rod 13 to the end of which, outside of said distributing-box, is secured a lever B and the door B is adapted to close the openings B in the operation of our invention. We also provide in the bottom wall of the distributing-boxA a plurality of openings C, provided with an outwardly-swinging door 0 secured to a transverse rod 0 which is provided at its outer endwith a lever 0 which is adjacent to the lever B and the doors 13 levers B and 0 is pivotally mounted a disk F, provided with a projecting arm G, and on the outer face of the disk F are two pins D and E, which are preferably near the edge of said disk and radially opposite each other, and Operating in connection with said pins D and E are two bars D and E which are pivoted at their other ends to the levers B and (3 respectively. We also pivot to the 'disk F, near the' edge thereof, an upwardlydirected arnV, which passes slightly above the top ol' the distributing-box A and is held in position on said distributing-box A by guides V and the upper end of the arm V, which projects above the distributing-box A, is preferably wedge-shaped, and all of this construction is clearly shown in the drawings.

Pivotally secured to the arm G of the disk F is a downwardly-direetedpiston-rod T, on the lower end of which is secured a piston T which closely fitsi into a dash-pot U, and the piston T is provided with a small conical hole passing therethrough, the larger end of which is at the top, and on one side of the dash-pot U are two openings W and W one at the top and the other atthe bottom thereof, and these openings W and W are connected by a pipe W provided with a check-valve W and in practice we partly fill the dashpot U with oil, and the weight of the piston descending causes part of said oil to ooze through the opening in the piston T and remain over said piston.

On the front wall X of the boiler X we provide a furuace-do'or X the bottom of which passes closely over the top wall of the distributing-box A, and the lower edge of the furnace door X is adapted to engage the wedge-shaped top of the arm V. We also provide the usual ash-pit 'doors or slides Q, which may be provided with air openings or vents, if desired. The hot-air pipes K and K may also be provided with fansor blowers at their rear ends, if desired, instead of the steam-jet for the purpose of forcing the draft, although we have not shown them in the drawings. 4 I

The fires are started and steam raised in 'the usual manner, and when the furnace is charged with green coal a greater amount of air is necessary over the top of the fire in order to consume the rising hydrocarbon gases, and when the furnace-door X is opened the lower edge thereof strikes against the inclined surface of ,the arm V, which is thereby forced downward, and thereby operates the disk F, to which it is pivoted, and the bars .D and E are also moved thereby, and with said arms D and E the levers B and 0 which are pivoted thereto', and the doors 13 and 0 are operated by said levers B and 0 the doors B opening downwardly into the distributing-box A and the doors 0 elosing partly, as shown in dotted lines in Fig. 3. As the disk F is partially revolved in the operation just described, the arm or handle G integral therewith is raised and carries with it the piston-red T and piston T secured thereto, and the oil which was above the piston T flows therefrom into the pipes W and back into the dash-pot U through the checkvalve W The fireman at this time or previously operates the valve R by means of` the rod S and allows steam from the supply-pipe to pass into the hot-air pipes K and K, and this steam forces air through said pipes, and, as hereinbefore described, the pipes K and K being placed within the escape-fine Y the air passing through said pipes is heated by the time it reaches the air-distributing box A and passing through the openings B into the f urnace-chamber above the fire-grates combines eagerly with the hydrocarbon gases rising from the green fuel when the fire is charged, and the heating of the air as just described is necessary to the proper opera tion of our invention, and the hot air not only mixes with the gases rising from the green .coal, but it also forms a layer of such air between the gases and the relatively cold plates of the top of the furnace-chamber, and the gases are' therefore consumed before reaching said plates by combining with said hot air and are not condensed by the said plates into the form of soot, and the formation of smoke is thereby prevented.

The reason for the construction of the dashpot U and the piston T is that while it permits of the rapid raising of said piston the descent of the same is necessarily slow, as the oil must ooze through the conical hole in the piston T before gravity can bring said piston to its lowest position, and as the operation is gradual the reversal of the position of the doors B and 0 is necessarily gradual, and the hot air therefore passes over the firegrates and combines and consumes the gases rising from the fresh coal until the piston T is entirely down, when the doors B'* are closed IOO IIO

This apparatus is simple in Construction and operation and is also comparatively in'- expensive, and by means thereof the production of carbon-laden smoke is almost if 'not entirely prevented, the amount of coal used is reduced to a minimum, and the efficiency of a boiler as a steam-generator is th usiargely increased.

Having fully described our invention', what we claim as new, and desire to secure by Letters Patent, is-

1. In an apparatus for supplying air to the furnace-chamber of a boiler, an air-box in communication with the furnace-chanber above and below the grate, and provided with doors controlling said communication, and means for Operating said doors consisting of levers in connection' with said doors, a disk mounted on said air-box, bars connecting said levers With said disk, an arm in connection with and adapted to operate said disk and provided with a wedge-shaped end projecting over the top of said air-box and adapted to be operated by the door of said furnacechamber, a dash-pot, a piston movable therein, and connected with said disk and provided with a conical hole through said pisten, and a pipe connecting the top and bottom of the dash-pot and provided with a check-valve substantially as shown and described.

2. A coal-saving and smoke-preventing apparatus for use in connection with a boiler comprising an air-distributing box located in the front of the furnace-chamber, air-pipes in connection therewith, means for heating and forcing air through said pipes into said box, doors opening from said box into the space above and below said grate, and devices for automatically and alternatively operatiug said doors, substautially as shown and described.

In testimony that we claim the foregoing 

